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Original question:

TMS320F2800137: dronecan

TMS320F2800137: The speed was also fluctuating

zhou qicheng
Intellectual 790 points

Part Number: TMS320F2800137
Other Parts Discussed in Thread: BOOSTXL-DRV8323RS

Tool/software:

Hello, when I used the official example C: \ Users \ xiaohua \ Desktop \ 013 \ x15 \ universal-motorControl_1ab_f280013x and the official development board BOARD_BSXL8323RS-REVA to drive the motor, I found that as the speed increased, the no-load bus current almost became a triangular wave, and the phase current was only about 22 A. The speed was also fluctuating. The effect of adjusting the current and speed loop pi was not significant, but later I found that the pi of id also worked,
1. Isn't the fast observer not using the d-axis? The weak magnetic flag is assigned a value of 0
Why does the no-load speed fluctuate and there is no significant change in adjusting pi? Which variable should be debugged
3. Should the moment of inertia be very accurate

  • 0
    TI__Genius 11076 points

    Hello,

    Apologies for the delay in response. First, please note that the BOOSTXL-DRV8323RS is a 15A board, not a 22A board. You may be running into HW limitations.

    For the FAST observer, the accuracy of the moment of inertia is important, particularly as you approach the edges of the motor's rated operating range.

    Before any further debug, are you certain the DRV8323RS is appropriate for the motor you're using?

    Regards,
    Jason Osborn

  • 0 in reply to Jason Osborn
    Intellectual 790 points

    Why is it necessary to adjust the pi of the d-axis? Otherwise, the no-load speed will be unstable. Can we make the d-axis 0? Because I used the official routine of the 027 chip before, and the d-axis was directly assigned to zero. I have never adjusted the pi of the d-axis. I am afraid that using the d-axis will increase the phase current,

  • 0 in reply to zhou qicheng
    TI__Genius 11076 points

    The d-axis is used in cases of, for example, the field-weakening control and maximum torque per-ampere control methods. See this document for further explanation of that concept. If you would like to manually adjust the code to force Id to 0, that is an option, but generally it should be fine.

    Regards,
    Jason Osborn

  • 0 in reply to Jason Osborn
    Intellectual 790 points

    Hello, I have assigned the d-axis value to 0 directly, obj->Vdq_out_V.value[0] = 0.0f; But strangely, I still need to adjust the pi of the d-axis. Why is that? I tried to mask the call to the d-axis pi function and found that the waveform has deteriorated. Is there a significant difference between fast and 027

  • 0 in reply to zhou qicheng
    TI__Genius 11076 points

    Apologies for the delay in response,

    I accidentally responded to the other thread, see response here.

    Regards,
    Jason Osborn